1. Field of the Invention
The present invention relates to a novel substituted phthalocyanine compound improved in solubility, and excellent in hue and fastness properties and a mixture thereof, an ink containing the phthalocyanine compound (mixture), an ink for ink jet recording (particularly, a water soluble ink), a method for improving the long-term storage stability of an ink, an ink jet recording method, an image forming method, and a method for improving the ozone gas resistance of the formed colored image material.
2. Description of the Related Art
In recent years, as image recording materials, particularly, materials for forming color images have been mainstream. Specifically, recording materials of an ink jet system, recording materials of a heat sensitive transfer system, recording materials of an electrophotographic system, transfer type silver halide light-sensitive materials, printing inks, recording pens, and the like have found widespread use. Whereas, in image pickup devices such as CCDs for photographing equipment, and in LCDs and PDPs for displays, color filters are used for recording/reproducing color images.
For these color image recording materials and color filters, (dyes and pigments) of three primary colors of a so-called additive color mixing process or subtractive color mixing process have been used in order to reproduce or record full-color images. However, in actuality, there is no fast coloring matter having the absorption characteristics capable of realizing a preferred color reproduction region, and resisting various use conditions. Thus, the improvement thereof has been strongly desired.
The ink jet recording method has rapidly come into widespread use, and has been under further development because of the low material cost, the capability of high-speed recording, less noise for recording, and further, easy color recording.
The ink jet recording method includes a continuous method in which droplets are continuously flown, and an on-demand method in which droplets are flown according to image information signals. The ejecting methods include a method in which droplets are applied with a pressure by a piezoelectric element, and ejected, and a method in which bubbles are formed in an ink by heat, so that droplets are ejected, a method utilizing an ultrasonic wave, or a method in which droplets are sucked and ejected by an electrostatic force.
Whereas, as the ink jet recording ink, a water base ink, an oil base ink, or a solid (molten type) ink is used.
The coloring matters for use in such al ink jet recording ink are required to be excellent in solubility or dispersibility in a solvent, to be capable of high density recording, to be good in, to be fast to light, heat, and active gases in the environment (oxidizing gases such as NOx and ozone, and in addition, SOx, and the like), to be excellent in fastness properties to water and chemicals, to be less likely to spread on an image-receiving material because of its good fixability, to be excellent in storability as an ink, to have no toxicity, to have high purity, and further to be available at low cost.
In a color copier or a color laser printer utilizing an electrophotographic method, generally, a toner obtained by dispersing a colorant in resin particles has been widely used. As the performances required of a color toner, mention may be made of the absorption characteristics capable of realizing a preferred color reproduction region, particularly, high transmittance (transparency) which matters in use for an overhead projector (below, OHP), and various fastness properties under the environmental conditions in which it is used. The toners obtained by dispersing a pigment in particles as a colorant are disclosed in JP-A-62-157051, JP-A-62-255956, and JP-A-6-118715. However, these toners are excellent in light resistance, but are insoluble, and hence tend to agglomerate, unfavorably resulting in a reduction of the transparency of the colored layer and a change in hue of the transparent color. On the other hand, the toners using a dye as a colorant are disclosed in JP-A-3-276161, JP-A-7-209912, and JP-A-8-123085. However, these toners are inversely high in transparency, and shows no change in hue. However, they have a problem in terms of the light resistance.
Heat sensitive transfer recording has the following advantages: the device is compact, and capable of being reduced in cost; the operation and the maintenance are easy; further, running cost is low; and the like. As the performances required of the coloring matter for use in heat sensitive transfer recording, mention may be made of the absorption characteristics capable of realizing a preferred color reproduction region, the compatibility between the thermal transferability and the fixability after transfer, the thermal stability, various fastness properties of the resulting image. However, no conventionally known coloring matter satisfies all these performances. For example, for the purpose of improving the fixability and the light resistance, the heat sensitive transfer recording material and the image forming method, wherein a thermally diffusible coloring matter has been previously added in the image-receiving material, and is allowed to chelate by transition metal ions are proposed in JP-A-60-2398, and the like. However, the absorption characteristics of the chelate coloring matter formed are at an unsatisfactory level, and use of the transition metal also causes environmental problems.
A color filter is required to have high transparency. Therefore, a method referred to as a dyeing method for coloring using a dye has been performed. For example, a dyeable photoresist is subjected to pattern exposure and development, thereby to form a pattern. Then, dyeing is carried out with a dye of the filter color. This method is sequentially repeated for all filter colors. As a result, it is possible to manufacture a color filter. It is also possible to manufacture a color filter with die methods using a positive type resist described in U.S. Pat. No. 4,808,501, JP-A-6-35182, and the like, other than the dyeing method. With these methods, a dye is used, and hence the transmittance is high and the optical characteristics of the color filter are excellent. However, there are limitations on the light resistance, the heat resistance, and the like. Thus, there has been a demand for a coloring matter excellent in various resistances, and high in transparency. On the other hand, a method using an organic pigment excellent in light resistance and heat resistance in place of a dye is widely known. However, with a color filter using a pigment, it has been difficult to obtain such optical characteristics as those of a dye.
The coloring matters for use in the respective applications are required to have in common the following properties. Namely, the absorption characteristics in terms of color reproduction are preferable; fastness properties under the environmental conditions in which they are used, such as the light resistance, heat resistance, moisture resistance, the resistance to an oxidizing gas such as ozone, fastness properties to chemicals such as sulfurous acid gas are good; the molar absorption coefficient is large; and other properties.
However, it is very difficult to seek a coloring matter satisfying these requirements at a high level. Particularly, it is strongly demanded for the coloring matter to have a good cyan hue, to be fast to light, humidity, and heat, and especially, to be fast to an oxidizing gas such as ozone in an environment for printing on an image-receiving material having an ink receptive layer containing porous white inorganic pigment particles. In addition, the compatibility with the ink storage stability is strongly demanded as described later.
The coloring matter skeletons of cyan for use in such ink jet recording ink include those of a phthalocyanine type, anthraquinone type, triphenylmethane type, and other types. A phthalocyanine compound excellent in hue and light fastness property is used. However, it does not have sufficient fastness properties to oxidizing gases, particularly, ozone, and cannot satisfy even the ink stability. This created a demand for the improvement thereof.
As typical phthalocyanine coloring matter most widely reported and used, mention may be made of the phthalocyanine derivatives classified into the following [1] to [6].
[1] Copper phthalocyanine type coloring matters such as Direct Blue 86 or Direct Blue 87 [e.g., a mixture of Cu-Pc-(SO3Na)m: m=1 to 4]. Incidentally, the term “Pc” in the formula and hereinafter used in this specification denotes the phthalocyanine skeleton.
[2] Direct Blue 199, and the phthalocyanine type coloring matters [e.g., a mixture of Cu-Pc-(SO3Na)m(SO2NH2)n: m+n=1 to 4] described in JP-A-62-19023, JP-A-63-28690, JP-A-63-306075, JP-A-63-306076, JP-A-2-131983, JP-A-3-122171, JP-A-3-200883, JP-A-7-138511, and the like.
[3] Phthalocyanine type coloring matters [e.g., Cu-Pc-(CO2H)m(CONR1R2)n: m+n=an integer of 0 to 4] described in JP-A-63-210175, JP-A-63-37176, JP-A-63-304071, JP-A-5171085, WO 00/08102, and the like.
[4] Phthalocyanine type coloring matter [e.g., Cu-Pc-(SO3H)m(SO2NR1R2)n: m+n=an integer of 0 to 4, and m≠0] described in JP-A-59-30874, JP-A-1-126381, JP-A-1-190770. JP-A-6-16982, JP-A-7-82499, JP-A-8-34942, JP-A-8-60053, JP-A-8-113745, JP-A-8-310116, JP-A-10-140063, JP-A-10-298463, JP-A-11-29729, JP-A-11-320921, and the like, EP 173476A2, EP 468649A1, EP 559309A2, EP 596383A1, DE3411476, U.S. Pat. No. 6,086,955, WO 99/13009, GB 2341868A, and the like.
[5] Phthalocyanine type coloring matters [e.g., Cu-Pc-(SO3H)1(SO2NH2)m(SO2NR1R2)n: 1+m+n=an integer of 0 to 4] described in JP-A-60-208365, JP-A-61-2772, JP-A-6-57653, JP-A-8-60052, JP-A-8-295819, JP-A-10-130517, JP-A-11-72614, JP-T-11-515047 (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application), JP-T-11-515048, and the like, EP 196901A2, WO 95/29208, WO 98/49239, WO 98/49240, WO 99/50363, WO 99/67334, and the like.
[6] Phthalocyanine type coloring matters [e.g., Cu-Pc-(SO2NR1R2)n: n=an integer of 1 to 5] described in JP-A-59-22967, JP-A-61-185576, JP-A-1-95093, JP-A-3-195783, EP 649881A1, WO 00/08101, WO 00/08103, and the like.
Currently commonly and widely used phthalocyanine dyes typified by Direct Blue 87 or Direct Blue 199, and also described in the foregoing publications, and the like feature more excellent light resistance as compared with Magenta and Yellow. However, they tend to cause a problem due to the solubility of the dyes. For example, often, dissolution failure occurs during manufacturing, resulting in manufacturing troubles, or insoluble matters precipitate during product storage or in use, causing problems. Particularly, in the ink jet recording previously stated, there are the following problems: the inferior ink storage stability as in precipitation of a dye or the like entails clogging of a printing head or an ejection failure, which causes noticeable degradation of a printed image; and other problems.
Further, fading also tends to occur due to oxidizing gases such as ozone often cited as an environmental problem recently, resulting in a large reduction of the printing density. This has become a large problem.
Currently, ink jet recording has rapidly expanded the range of field of use. When it is used more and more widely in ordinary households, SOHOs, commercial fields, and the like, it is exposed to various working conditions and use environments. As a result, more often, troubles of the ink storage stability due to the dissolution failure of a cyan dye occurs, or the printed image is exposed to light or active gases in an environment, unfavorably resulting in fading thereof. Therefore, there has been an increasingly strong demand for a coloring matter and an ink composition each having a particularly good hue, excellent in light fastness property and active gases in an environment (such as SOx, other than oxidizing gases such as NOx and ozone), and having high solubility.
Until now, the phthalocyanine coloring matters imparted with the ozone gas resistance are disclosed in respective publications such as JP-A-3-103484, JP-A-4-39365, and JP-A-2000-303009. However, in actuality, all fall short of having both hue and the fastness properties to light and oxidizing gases. Particularly, for the ozone gas resistance, there has been no example, so far, of the report regarding the properties of the coloring matter serving as a guide. Further, although there has been a report of use of the phthalocyanine type coloring matters described in EP 1243626A1, EP 1243627A1, and the like, the density dependence of the fastness properties is large (implementation of fastness only at a high density portion), and light is reflected by occurrence of a bronzing phenomenon at the high density portion. Accordingly, not only the optical density of the recorded image is reduced, but also the hue of the recorded image becomes largely different from the desired one. Thus, in actuality, the coloring matters fall short of the level capable of satisfying the required performances.
Whereas, when the azaphthalocyanine compounds described in WO 02/34844 are used, when each is used as an ink (particularly, a cyan dye), the azaphthalocyanine compounds described above remarkably show a short wavelength shift in hue. As a result, they are not at such a level as to be able to satisfy the absorption characteristics capable of realizing a preferred color reproduction region. Further, the change of the central metal of the metal phthalocyanine compound (e.g., Ni) has some effect on the improvement of the hue (long wavelength shift). This, however, results in the level which cannot be said to be the absorption characteristics capable of realizing a preferred color reproduction region, and is attended with further problems such as a problem of material safety due to the use of Ni.
On the other hand, as an ink of ink jet recording method (hereinafter, the latter is also referred to as an ink jet recording ink), a water base ink is mainly used. The water base ink is basically composed of a coloring matter, water, and an organic solvent, and contains water as a main solvent from the attention to the odor, the human body, and the safety to the surrounding environment. Whereas, as the coloring matter, generally, a water soluble dye such as an acidic dye, a basic dye, a reactive dye, or a direct dye is used.
For such ink jet recording inks (and dye), mention may be made of the following various required characteristics.
Namely,
(1) The physical property values such as viscosity, surface tension, specific electric conductivity, density and pH of the ink are proper;
(2) The long-term storage stability of the ink is good;
(3) The dissolved component has high solubility stability, and hence does not cause clogging of the nozzle;
(4) The rapid drying properties on a recording material is good;
(5) The recorded image is sharp, and the light resistance, and the water resistance are good;
and the like.
However, a conventional ink falls short of satisfying all these characteristics.
In the case of a commonly used water base ink, a water soluble dye is used. For this reason, when water splashes on the recorded image, the dye dissolves out, so that the recorded image may become blurred, or vanish. As in this and other cases, there is a large problem in terms of the water resistance. Particularly, the clogging of the head in the ink jet recording method is a problem. Currently, various studies have been made aiming at the ink storage stability:
For example, studies have been made on the methods in which to an ink using a pigment or an oil soluble dye as a coloring matter, or to a water base ink using a water soluble dye, an organic solvent, a resin, or the like is added. However, the ink using a pigment is unfavorably bad in dispersion stability, inferior in storage stability, causes clogging of the nozzle, and causes other problems. Whereas, for the ink using an oil soluble dye, an organic solvent is used. Therefore, there have been problems in terms of the environmental health such as odor, or unfavorably, the reduction of the image quality have been caused because of a large spread of the ink, and other problems have been caused. Whereas, also in the case of the ink to which additives were added, there has been a problem such as inferior storage stability, clogging of the nozzle, or poor flying of an ink because of the increase in viscosity of the ink.
The disclosures in JP-A-2000-303014, JP-A-2000-313837, and the like relate to a phthalocyanine pigment improved in dispersion stability and showing excellent storage stability. However, all fall short of having both hue and the fastness properties to light and oxidizing gases, thus not leading to the provision of products well satisfying market's requirements.
Recently, JP-A-6-340835, JP-A-12-239584, WO 00/08102, and the like describe an ink using a water base dispersion containing a polyester resin colored by a dye or a pigment as a dispersoid. However, even by using this method, the foregoing problems have not been yet solved well. On the other hand, also for the dye, it is described that the compatibility with the resin directly involved in the reduction of the image density, the reduction of the water resistance, the storage stability, clogging of the nozzle, and the like, and the control of the average particle diameter of colored resin fine particles are problems.
Whereas, generally, for the phthalocyanine compound (mixture), as described in WO 00/17275, WO 00/08103, WO 00/08101, WO 98/41853, JP-A-10-36471, and the like, when an unsubstituted phthalocyanine compound is sulfonated, and used as a water soluble dye, it is used as it is in the form of an alkali metal salt, such as a sodium salt, of the sulfonated compound. When it is derived to an oil soluble dye, the one synthesized through the sulfonyl chloridation and amidating reaction after sulfonation can be used.
For a conventionally used aqueous cyan ink for ink jet, a water soluble dye such as a copper phthalocyanine compound having a sulfo group or a salt of a sulfo group as a substituent obtained by sulfonating a copper phthalocyanine compound is used.
In this case, sulfonation may take place at any site of the phthalocyanine nucleus, and furthermore, the number of sites to be sulfonated is difficult to control. Accordingly, when a sulfo group is introduced under such reaction conditions, the site and the number of sulfo groups introduced into the product cannot be specified, and a mixture of those differing in the number of substituents or in the substitution site is inevitably produced.
This results in mixing of a component low in solubility, for example, a component in which sulfonation has occurred only at zero or one site relative to the phthalocyanine nucleus into the mixture. As a result, the solubility tend to be insufficient for use as a water soluble dye. This has caused a demand for the improvement of the solubility.
On the other hand, as an oil soluble dye, a phthalocyanine compound having an ammonium salt of sulfonic acid containing an ion pair of a sulfamoyl group and/or a sulfo group is known. The phthalocyanine compound is manufactured in the following manner. A metal phthalocyanine compound is chlorosulfonated with chlorosulfonic acid. Then, the chlorosulfonated form of the phthalocyanine compound taken and obtained and an amine compound are allowed to react with each other (e.g., RIRONN SEIZOU SENRYOU KAGAKU written by Yutaka Hosoda, fifth edition, issued on Jul. 15, 1968, published by GIHODO Publisher's Co., pages 798 to 799). With this manufacturing method, in the reaction of the chlorosulfonyl form of a phthalocyanine compound and an amine compound, a sulfonic acid amide group is formed. In addition, chlorosulfonyl groups are partially hydrolyzed, and remain as sulfo groups, and a phthalocyanine compound containing an ammonium salt of sulfonic acid in which ion pairs of sulfo groups and an amine compound have been formed.
When the phthalocyanine compound thus obtained is used as a coloring matter for ink jet recording, the solubility of the ink in a solvent is low, which unfavorably makes it impossible to prepare an ink, nor to manufacture an ink with a necessary density, and causes other problems. Further, under the effects of the remaining sulfo groups, blur may occur upon printing on ordinary paper, or the water resistance of the recorded image may be deteriorated, and undesirable effects may be imposed on other various characteristics.
Thus, the various characteristics of the ink, particularly the ink for use in the ink jet recording method largely depend upon the characteristics inherent in the coloring matter. Therefore, it is very important to select a coloring matter satisfying the foregoing various conditions.
JP-A-2003-34758 discloses a phthalocyanine compound (mixture) having a pyridine ring, a pyrazine ring, and a benzene ring. There is a demand for a phthalocyanine compound with limited substituents and substitution sites, and further improved in fastness properties (particularly, ozone resistance).
JP-A-2004-75986 describes a phthalocyanine compound having fastness properties to light, heat, humidity, and active gases in an environment. However, the compound has an ionic hydrophilic group, and hence it is low in solubility in an oil base dye, and inferior in dispersibility. Further, blur occurs upon printing on ordinary paper, or the water resistance of the recorded image is deteriorated. These result in a demand for further improvements thereof.